Chinese state media has criticized anti-US protests outside KFC outlets across China as jingoistic, saying they do "a disservice to the nation".
The protesters are angry about an international tribunal ruling rejecting China's territorial claims in the South China Sea.
The case was brought by the Philippines, a US ally which has a competing claim in the area.
State newspapers said the authorities were "calling for rational patriotism".
KFC has more than 4,000 branches in China and is often seen as a symbol of US influence in the country.
How big have the protests been?
Not huge, but animated.
In recent days, small groups of protesters have gathered outside KFC outlets, starting in Hebei and spreading to other places including Changsha and Hangzhou, media reports said.
They have shouted anti-US slogans and held up banners with the words "Get out of China, KFC and McDonalds".
In some of the videos of protests which were posted to Sina Weibo, police can be seen intervening.
What have state media said?
The state Xinhua news agency said: "This is not the right way to express patriotism."
The China Daily newspaper said: "Instead of being patriotic, it is their jingoism that does a disservice to the spirit of devotion to the nation.
"Those who organize such activities without going through the necessary procedures and unlawfully harass others in the name of patriotism should be held accountable according to the law."
Both the China Daily and the People's Daily newspaper said police and media organizations were "calling for rational patriotism".
In China, protesting without seeking permission from the authorities is forbidden.
But what does KFC have to do with the tribunal?
Nothing. However, China has accused the US of encouraging its ally, the Philippines, to challenge China in the arbitration tribunal.
The tribunal ruled there was no evidence for China's claim of historic rights to the waters or resources within its "nine-dash line", and that it was violating the Philippines' sovereign rights with its operations there.
China has been engaged in vast amounts of construction on various disputed islands and its maritime authorities have been involved in altercations with Philippine fishermen in the Scarborough Shoal area.
China refused to participate in the proceedings and rejected the findings.
Is it just KFC?